In order to study the effect of temperature on airborne imaging spectrometer optical performance, the characteristics of the instrument under temperature load onboard were analyzed, the mechanism and manifestations of temperature load were described, the thermal performance of the spectrometer was studied. Firstly, the characteristics of the temperature load under airborne was analyzed. Secondly, the least squares method and coordinate transformation method were taken as the theoretical basis for the preparation of the surface error and rigid displacement solver, combined with the finite element method to calculate the deformation and rigid body displacement of the mirror of the optical systems at a temperature load. Finally, a ray tracing was used to solve the mirror line position change due to displacement of the rigid body displacement, study its spectral drift, and calculate the effect of the rigid body displacement on the modulation transfer function(MTF). The results show that within the range ±10 ℃, line drift is less than 1/3 of the required accuracy of spectral calibration, no further spectral calibration and correction is needed.